Milkweed gin



Feb. 25, 1941- B, BERKMAN 2,233,156

MILKWEED GIN Original Filed March 1'7, 1939 2 Sheets-Sheet 1 B. BERKMANFeb. 25, 1941.

MILKWEED GIN Original Filed March 1'7, 1939 2 Sheets-Sheet 2 PatentedFeb. 25, 1941 UNITED STATES MILKWEED GIN Boris Berkman, Chicago, Ill.,assignor to Milkweed Products Development Corporation, Ohicago, 111., acorporation of Illinois Original application March. 17, 1939, Serial No.262,421. Divided and this application June 21, 1939, Serial No. 280,317

4 Claims.

The present invention relates to an apparatus for a carrying out thismethod.

One object of my invention is the separation of the floss and seeds fromthe pods.

Another object of my invention is to provide a method of curing themilkweed pods after harvesting to facilitate the opening of the pods andseparation of the contents and to prevent fermentation and decompositionof the pods.

' Another object of my invention is to provide a method of separatingthe floss from the seeds to which it is normally attached.

Another object of my invention is to provide means for collecting andaccumulating air-borne milkweed floss.

Another object of my invention is the production, as a new article ofmanufacture, of a milkweed floss. free of the seeds normally attachedthereto and of the pods normally surrounding the same, having the novelcharacteristics of great looseness, elasticity, and insulating value,composed of smooth, hollow fibers containing approximately sixty percentof cellulose.

Further objects and advantages of my invention will become apparent uponreading the following specification in conjunction with the attacheddrawings, of which:

Fig. 1 is an elevation of apparatus for carrying out the separation andcollection of milkweed floss and seeds from the pods:

Fig. 2 is a flow sheet of my method of floss and seed separation andcollection as carried outby the apparatus illustrated in Fig. 1; and

Fig. 3 is a flow sheet analogous to Fig. 2, butmodified to illustratehow my methods can be adapted to continuous production.

From time immemorial the lowly milkweed has been a source of annoyanceto the industrious farmer, gardener, and husbandman. This common weed ismarked by its persistence, hardiness, adaptability to extremelyunfavorable conditions, and remarkable reproductive facilities, all ofwhich qualities have heretofore contributed only 1 to its reputation asan agricultural pest, for it is both detrimental to cultivated crops andpoisonous to animals. Therefore, with the exception of some strikinglyunsuccessful attempts to produce rubber from its milky juice, the planthas been subject more to attempts at extermination than to scientificappraisal and utilization of its multitudinous valuable properties.

The common milkweed is a perennial plant, three to seven feet tall,having hollow woody stalks nourished by an extensive root system. Thestalks are suitable for the manufacture of a superior grade ofinsulation board and pressed board according to a method disclosed in, acopending patent application. The extensive root system of the milkweedmakes this plant preeminently suitable for the control of soil erosion.A system of erosion control based on the use of milkweed plantings hasbeen developed and is the basis of another copending patent application.The stalks of the milkweed bear a'plurality of pods, from five tothirty-five, which reach maturity in autumn, usually during the month ofOctober in the middle western or north central regions of the UnitedStates. These pods contain the multitude of seeds with which the plantreproduces itself. Eachindividual seed is fitted with a group of seedhairs, forming a parachute which, because of its voluminous lightness,is caught by the breeze as the enclosing pod bursts, and is blown farfrom the mother plant, carrying the attached seed along with it. Thepods burst soon after maturity, scattering their contents, which aresometimes carried miles away by the wind. The present notoriety of themilkweed is due partly to this eflicient method of scattering its seeds.

Contemplative students of nature have often speculated upon thecommercial possibilities of the seed and of the beautiful silky floss ofthe milkweed plant, but have never attempted practically to realizethem. At least, I am not aware of any successful attempts so to do. Ihave found, on the other hand, that both the floss ,and the seeds of themilkweed have many vain-- able properties, whose utilization is subject,however, to the successful solution of the problem of economicallyopening the still closed pods after their harvest, separating the seedsand floss therefrom, and separating the floss from the seeds to which itis normally attached.

The seeds are valuable for their content of semi-drying oil, of aquality akin to soya-bean oil, and their high protein content whichindicates potential value as an animal food. The seeds are, in fact,similar in many other respects to soya beans. The utilization of theseeds is not an object of this patent, however, and I shall thereforenot amplify the discussion thereof, except to point out that up to thepresent the commercial utilization of the seeds has awaited thedisclosure of a successful method of separating them from the pods andthe floss, such as the I one I am about to describe.

I have found that the floss possesses a large number of uniqueproperties, which make it suitmirably qualify it for these uses are itselasticity or springiness, which cause itto fill confined spaces andwhich prevents packing of the floss after long periods of time; its lowcoefiicient of heat conductivity, which is due partly to the air spacesbetween the fibers, and partly to the air within the hollow fibersthemselves; its light of the two fibers is remarkable. Milkweed floss issomewhat superior to kapok in many respects, however. For instance, itscoefficient of heat transmission is lower than that of kapok.

Milkweed floss is undoubtedly superior to kapok from the standpoint ofagricultural economics. Kapok must be imported from Java or thePhilippines, where it is produced in a very haphazard manner by thenatives. There is much variation in the quality of the fiber, which isoftendue to adulteration. The .kapok tree is not aprolific bearer andrequires about eight years to reach maturity. The trees are easilydamaged, and picking of the kapok pods is diflleult. Kapok treesareuseful only for the production of floss. Milkweed, on the other hand, isa perennial yielding yearly crops, and twice yearly crops in the South.A large yield of floss per acre is obtainable. Milkweed yields manyother valuable products in addition to the floss, such as the insulatingwallboard, pressed board, drying oil, and animal food previously alludedto. Furthermore, the outer or bast fibers of the stalk, which containabout 93% of alpha-cellulose, can be separated by a process disclosed inone of my copending patent applications, for use in the manufacture ofrayon, Cellophane, dynamite, and textile fibers. The remaining woodyfiber can be converted into paper and plastics.

The milkweed crop is easily harvested. Milk-.

weed is an American crop capable of producing untold benefits to theAmerican farmer, and not subject to the uncertainties attending theimportation of foreign raw materials.

My method of floss liberation is applicable to most species of thegenus, Asclepias of the family Asclepiadaceae, although I have foundthat the describe these units separately, but shall indicate theircooperation during the course of the description. i

The curing floor I shown in Fig. 1 may be any dry warehouse or loftfloor upon which the pods are spread to dry. The pods must be spread asa thin layer, preferablyon racks which will allow free circulation ofdry air over the pods. It is often advisable to preheat the air andforcibly to circulate it over the pods in order to insure adequatedrying.

I have found that the proper degree of curing is of the utmostimportance to the successful utilization 'of milkweed pods. Propercuring of the pods causes them to burst readily and makes possible theefiicient separation of the floss from the seeds to which it is normallyattached. Curing of the pods is completed when their moisture content isapproximately thirty percent by weight. The moisture content is rathercritical, for separation of the floss and seeds and opening of the podsbecomes difficult if the moisture content specified above is exceeded.

Cured pods may conveniently be stored in a large hopper 3 intowhich theyare charged through a hatch 2 in the curing floor. Pods are removed fromhopper 3 as required by manipulating the gate 4 closing the lower end ofthe hopper 3.

The pod separator consists of a large hopper shaped container 5 whoselower constricted end is connected to a powerful blower 6, and also to achute 1. The blower'6 and pod separator 5 are severally supported upon asuitable framework 8. The hopper 5 is divided into receiving compartment9 and an agitating compartment III by means of a door II. The top of theagitating compartment is covered with a grating l2 and communicates witha duct 13 of generous diameter. The grating l2 has openings which allowfloss and seeds to pass, but which retain the empty pods.

In operation the compartment 9 is filled with a supply of pods. The doorI l is opened, allowing the pods to drop into the agitating-chamber l0,and the door is closed again. The blower 6 is then set in operation,creating a strong blast of air which violently agitates the pods in theseparator, tumbling them against each other and against the grating.Because the pods have been cured they readily burst, dischargingtheircontents, which are blown through the grating l2 and pass into ductIS. The relatively heavy substantially continuousoperation of theplantmay be maintained.

The seeds and the floss attached thereto are carried to the agitatingchamber l6 of the seed and floss separator l5. This chamber isconstructed of materials pervious to'air, but retaining the floss. Suchmaterials may suitably be vscreen wire backed with cloth. The bottom ofchamber l6 is closed by a counter-balanced gate H. The agitating chamberis fitted with .a mechanical agitator consisting of two oppositelygeared rotating shafts l8 fitted with smooth paddles l 9 separated by atleast the length of the floss fiber. The gate l1 opens into a large flota' tion chamber 20, having a ventilator screen 2| in one side thereof,anda gate' 22 in the conical bottom thereof for the discharge of seeds.A spacious duct 23 communicating with an exhaust fan enters the upperportion of' the flotation chamber 20. This chamber, the agitationchamber I 6, a motor 30, and a speed'reducing transmission 3l fordrivingthe two agitator shafts l8 are supported upon the same rigid framework 8which supports duct I 3 and the pod separator 5.

In operation the air-home floss and seeds carried through duct l3 arecollected in chamber Hi, the air escaping through the pervious wallsthereof. Gate I1 is normally closed so that a sufiicient quantity ofmilkweed floss may accumulate in the chamber to engage the agitators.The revolving agitators effectively separate the floss from the seeds towhich it-is normally attached if proper curing of the pods has precededthis operation. It is important, however, that 'the agitators be smoothand their blades be smooth and openly spaced, because the floss,although it is springy and elastic, is readily injured if the individualfibers are subjected to extreme bending or shearing stresses. Atintervals of suflicient duration to insure complete separation, smallportions of the accumulated floss and seeds are dischargedfrom theagitator into the flotation chamber 20 by the operation of gate H. Theseeds drop to the bottom of the chamber from which they'may be removedat intervals to a. waiting lorry 29 by opening gate 22.

The floss is waftedup into the duct 23 by-the current of air enteringthe flotation chamber 26 via ventilator 2| under the influence of thesuction pump with which duct 23 communicates. This ,current of air isnot strong enough however to carry along the seeds. The floss and seedseparator may be operated continuously by keeping gate I! openedslightly, or by some similar expedient, whereby a quantity of floss isat all times being subject to agitation in chamber I 6. This isnecessary because separation of floss and seed is effective only if thefloss is somewhat packed.

Duct 23 terminates in a flange 24 to which may be tied a burlap sack 25for receiving the airborne floss from the flotation chamber. The end ofthe duct and the sack are enclosed in a hou's ing 26 communicating withan exhaust fan 21. The housing is provided with a tightly fitting dooryielding convenient access to the. bag of floss. A suitable supportingplatform may also be provided, as at 28. I v In operation the air-bornefloss from the airflotation chamber 20 is sucked through duct 23 andinto bag 25, where it is retained and where it accumulates and packsuntil the bag is full. The air is sucked through the'bag and out of thehousing 26 by the exhaust fan 2'|. Thefloss collected in the bag 25 is aunique product. Although such floss has been experi mentally producedprior to my invention by manually separating floss from milkweed seedsin small quantities, never before has a sufficient quantity beenaccumulated-to display its peculiar characteristics in the mass,particularly its properties of heat insulation. Nor, to my knowledge,has a floss free from all seeds, pods, and impurities ever been preparedin quantity. Such a floss, having smooth, hollow, elastic fiberscontaining about sixty percent of cellulose is a new product ofmanufacture'resulting from the application of the methods I havedescribed.

The milkweed floss liberation plant illustrated in Fig. 1 is representeddiagrammatically by the flow-sheet of Fig. 2. Ripe green pods aredelivered to the curing fl6or and the dried pods after curing are storedin hopper 3, from which quan- 1 plant which permits continuousoperation. The

flow-sheet of Fig. 3 illustrates this arrangement.

The-

This flow-sheet is identical with Fig. 2, except that three podseparators are provided which are operated in rotation, so that podseparation is going on at all times, thus allowing the separators to becharged with pods without interrupting the continuous operation of theother apparatus. A plurality of floss collectors 25 are provided for asimilar reason, so that full bags of floss may be replaced by empty bagswithout interrupting the flow of floss from the air flota tion chamber20 I recognize that other modifications of the arrangement andconstruction of my apparatus are possible, therefore, I wish to belimited only by the following claims.

I claim:

1. An apparatus for separating and removing the floss and seeds frommilkweed pods comprising an inverted conical chamber within which saidpods are agitated to cause them to burst and to discharge their contentof floss and seeds, retaining means covering the top of said chamberallowing the passage of said floss and seeds but retaining the emptyshells, and means for creating a current of air through the said chamberto agitate the pods and to remove the floss and seeds therefrom, saidcurrent creating means being located at the apex of said conicalchamber.

2. An apparatus for removing the floss'and seed from milkweed podscomprising an inverted conical agitation chamber, a grating across anopening in the roof of said chamber allowing the passage of said flossand seeds but retaining the empty shells, and means for introducing astrong current of air into said chamber violently to'agitate said podswhereby they are caused to burst and their. contents are expelledthrough said grating, said last mentioned means being located at theapex of said conical chamber.

3. An apparatus for separating milkweed floss from the seeds comprisinga chamber open at ing revolving agitators having blades arranged atsufficient intervals' from each other and havin such smoothness ofcontour as'will allow the efflbers, and means at the exit end of saidcham-' her to separate the floss from the seeds.

4. An apparatus-for the separation and collection of the component partsof milkweed pods, Y comprising means for strongly agitating the pods 60charge their contents of floss and seeds, means wherebythey are causedto burst andto disfor separating the seeds and floss from theempty pods,an agitating chamber including mechanism for seperating the floss fromthe seeds to which it is normally attached, means for transferring thefloss and seeds from the first mentioned means to said agitatingchamber, means for removing the floss from the free seeds byselectiveair flotation, means for transferring quantities of free flossand seeds from said agitating chamber to the last said means, and meansfor collecting the air-borne floss from said air-flotation means. v

BORIS BERK'MAN.

-ficient separation of the floss from the seeds but P will preventinjury and breakage of the floss

